Inner platform impingement cooling by supply air from outside

Abstract

A stator blade assembly for a gas turbine engine having; an outer shroud with an air supply port in communication with compressed air from a high pressure stage of a compressor of the engine; an inner shroud including a blade platform and a plenum enclosure defining a plenum bounded by an inner surface of the blade platform; and a blade spanning between the outer and inner shrouds. The blade has a leading edge portion with a passage communicating between the plenum and the air supply port of the outer shroud and an internal blade cooling channel communicating between the passage and apertures adjacent the trailing edge of the blade. The plenum includes an impingement plate disposed a distance from the inner surface of blade platform to define an impingement cooling chamber within the plenum, and the plate includes impingement cooling apertures to direct cooling jets of air at the inner blade platform. An air flow restriction plate covers the inner end of the passage and controls the pressure and quantity of air delivered to the plenum via a compressed air metering aperture. Preferably the impingement plate and flow restriction plate are manufactured as a one-piece unitary cover plate sealed to the inner surface of blade platform and covering the inner end of the passage.

Dependencies are inferred from the claim text.